Before hosting Hour 25 Warren James worked at J.P.L. for many years as well as doing other space related jobs. One of the first times he was heard on Hour 25 was just after the Challenger accident when he joined Mike Hodel on the air to pay tribute to the crew and talk about his reaction to the explosion of the shuttle. He later joined the show as one of the hosts taking turns, once a month, doing broadcasts during the era of rotating hosts; maybe a strange way to describe it but it's the best I can come up with. He has been hosting the show by himself for almost a decade now.